Magcargo's shell is actually its skin that hardened as a result of cooling. Its shell is very brittle and fragile—just touching it causes it to crumble apart. This Pokémon returns to its original size by dipping itself in magma.

1. Immune refers to taking 0.51x damage when attacking or defending.
2. Not Very Effective refers to taking 0.714x damage when attacking or defending.
3. Very Effective refers to taking 1.4x damage when attacking or defending.
4. Base Stamina/Attack/Defense are what this Pokémon start at. Individual values (IVs) add a max of +15 to each.
5. Base Flee Rate is only the base. Additional factors come into play.